Rotating pumping apparatus with seal mechanism

Abstract

A rotating pumping apparatus is provided which may be employed in an automotive brake system. The rotating pumping apparatus includes a sealing member and an oil seal which are disposed around a pump drive shaft, and lubricating grease disposed between the oil seal and the pump drive shaft. The sealing member is made up of a resinous ring and a rubber cup. The sealing member has formed therein a labyrinthine flow path which extends from the resinous ring to the rubber cup. The labyrinthine flow path is designed to permit fluid to flow therethrough and create the resistance to flow of the lubricating grease to avoid leakage of the grease outside the sealing member.

What is claimed is: 
     
       1. A rotating pumping apparatus comprising:
 a rotating pump; 
 a shaft which drives the rotating pump; 
 a casing which has formed therein a hole in which the shaft is disposed; 
 a sealing member which is disposed around the shaft between an inner periphery of the hole and an outer periphery of the shaft and creates a hermetical seal between the inner periphery of the hole and the shaft, the sealing member being equipped with a resinous ring and a rubber cup fit on an outer periphery of the resinous ring, the rubber cup having formed in the outer periphery thereof a first groove which extends in an axial direction of the shaft; 
 an oil seal which is disposed around the shaft between the inner periphery of the hole and the outer periphery of the shaft and creates a hermetical seal between the inner periphery of the hole and the shaft; and 
 lubricating grease disposed between the oil seal and the shaft, 
 wherein the resinous ring has an end surface which faces the oil seal and is located closer to the oil seal than the rubber cup is, the end surface having formed therein a second groove which extends from an inner space of the resinous ring to an outer periphery of the resinous ring, 
 wherein the second groove defines a labyrinthine flow path which has sections extending in a radial direction and a circumferential direction of the resinous ring, respectively, 
 wherein the sections of the second groove extending in the radial and circumferential directions of the resinous ring are connected through a bend, 
 wherein a length of the second groove is greater than a width in a radial direction of the resinous ring, and the second groove has an inlet and an outlet which are offset from each other in a circumferential direction of the resinous ring; 
 wherein the sections extending in the radial direction and the circumferential direction include a first radial section, a second radial section and a circumferential section, the first and second radial sections being in fluid communication through the circumferential section; and 
 wherein a first bend connects the first radial section with the circumferential section and a second bend connects the second radial section with the circumferential section. 
 
     
     
       2. A rotating pumping apparatus as set forth in  claim 1 , wherein the second groove formed in the end surface of the resinous ring has sections extending in the radial and circumferential directions of the resinous ring. 
     
     
       3. A rotating pumping apparatus as set forth in  claim 2 , wherein an outer end of the second groove which opens on an outer periphery of the resinous ring is offset from an end of the first groove in the circumferential direction of the sealing member. 
     
     
       4. A rotating pumping apparatus as set forth in  claim 3 , wherein the rubber cup also has formed in the outer periphery thereof a total of n first grooves which include said first groove, each of the first grooves extending in the axial direction of the shaft, wherein the resinous ring also has a total of n−1 or n+1 second grooves which include said second groove, each of the second grooves extending from the inner space of the resinous ring to the outer periphery of the resinous ring and having an outer end which opens on the outer periphery of the resinous ring, and wherein the outer ends of at least n−2 of the n−1 or n+1 second grooves are arranged out of alignment with ends of the first grooves, respectively, in the radial direction of the sealing member. 
     
     
       5. A rotating pumping apparatus as set forth in  claim 2 , wherein one of the sections of the second groove directed in the circumferential direction of the resinous ring leads from the inner space of the resinous ring in a direction opposite in a direction in which the shaft rotates. 
     
     
       6. A rotating pumping apparatus as set forth in  claim 1 , wherein the second groove extends in the end surface of the resinous ring in the radial direction of the resinous ring and has an outer end which opens on the outer periphery of the resinous ring, the outer end being offset from the first groove in the circumferential direction of the sealing member to form a portion of a clearance between the outer periphery of the resinous ring and an inner periphery of the casing as being one of the sections of the labyrinthine flow path which extends in the circumferential direction of the resinous ring. 
     
     
       7. A rotating pumping apparatus as set forth in  claim 4 , wherein the second grooves communicate with the first grooves to define labyrinthine flow paths, respectively. 
     
     
       8. A rotating pumping apparatus comprising:
 a rotating pump; 
 a shaft which drives the rotating pump; 
 a casing which has formed therein a hole in which the shaft is disposed; 
 a sealing member which is disposed around the shaft between an inner periphery of the hole and an outer periphery of the shaft and creates a hermetical seal between the inner periphery of the hole and the shaft, the sealing member being equipped with a resinous ring and a rubber cup fit on an outer periphery of the resinous ring, the rubber cup having formed in the outer periphery thereof a first groove which extends in an axial direction of the shaft; 
 an oil seal which is disposed around the shaft between the inner periphery of the hole and the outer periphery of the shaft and creates a hermetical seal between the inner periphery of the hole and the shaft; and 
 lubricating grease disposed between the oil seal and the shaft, 
 wherein the resinous ring has an end surface which faces the oil seal and is located closer to the oil seal than the rubber cup is, the end surface having formed therein a second groove which extends from an inner space of the resinous ring to an outer periphery of the resinous ring, 
 wherein the second groove defines a labyrinthine flow path which has sections extending in a radial direction and a circumferential direction of the resinous ring, respectively, 
 wherein the sections of the second groove extending in the radial and circumferential directions of the resinous ring are connected through a bend, 
 wherein a length of the second groove is greater than a width in a radial direction of the resinous ring, and the second groove has an inlet and an outlet which are offset from each other in a circumferential direction of the resinous ring; 
 wherein the sections extending in the radial direction and the circumferential direction include a first radial section, a second radial section and a circumferential section, the circumferential section being disposed between the first and second radial sections; and 
 wherein a first bend connects the first radial section with the circumferential section and a second bend connects the second radial section with the circumferential section. 
 
     
     
       9. The rotating pumping apparatus as set forth in  claim 1 , wherein the second groove formed in the end surface of the resinous ring forms a path that has at least one bend. 
     
     
       10. A rotating pumping apparatus comprising:
 a rotating pump; 
 a shaft which drives the rotating pump; 
 a casing which has formed therein a hole in which the shaft is disposed; 
 a sealing member which is disposed around the shaft between an inner periphery of the hole and an outer periphery of the shaft and creates a hermetical seal between the inner periphery of the hole and the shaft, the sealing member being equipped with a resinous ring and a rubber cup fit on an outer periphery of the resinous ring, the rubber cup having formed in the outer periphery thereof a first groove which extends in an axial direction of the shaft; 
 an oil seal which is disposed around the shaft between the inner periphery of the hole and the outer periphery of the shaft and creates a hermetical seal between the inner periphery of the hole and the shaft; and 
 lubricating grease disposed between the oil seal and the shaft, 
 wherein the resinous ring has an end surface which faces the oil seal and is located closer to the oil seal than the rubber cup is, the end surface having formed therein a second groove which extends from an inner space of the resinous ring to an outer periphery of the resinous ring, 
 wherein the second groove defines a labyrinthine flow path which has sections extending in a radial direction and a circumferential direction of the resinous ring, respectively, 
 wherein the sections of the second groove extending in the radial and circumferential directions of the resinous ring are connected through a bend, 
 wherein a length of the second groove is greater than a width in a radial direction of the resinous ring, and the second groove has an inlet and an outlet which are offset from each other in a circumferential direction of the resinous ring; 
 wherein the second groove formed in the end surface of the resinous ring forms a bath that has at least one bend; and 
 wherein a first bend connects the first radial section with the circumferential section and a second bend connects the second radial section with the circumferential section.